Originally indicated as an alarm alert in a 1990s US publication, this circuit can be used as a shield to control a strobe lamp. The sensor is a optocoupler with LDR.
This integrated amplifier was found in a non-existent British magazine from 1975. The used...
This is another quick adder that we found in an Electronic Design from the 80s. It also applies to...
This TTL siren is formed by two oscillators using each two Gates of a 7400. Frequency or the...